CN1790346A - Urban rainwater pipeline design method - Google Patents

Abstract

The invention discloses a design method of urban rainfall pipe, which comprises the following steps: 1. inputting the urban rainfall primitive data in the computer at the database or test pattern; 2. calling the primitive rainfall data from hard disk to CPU to finish the data; 3. proceeding frequency analysis of disposed data to obtain the i-t-P list; 4. calculating the i-t-P list through calling the 'confining stable convergence accelerating genetic algorithm program' by computer; obtaining the urban storm strength formula; 5. calculating the urban rainfall pipe diameter according to the storm strength formula. The invention improves the formula counting speed and calculation precision and avoids artificial error to reduce the formula error, which is an important supplement for present urban storm strength formula.

Description

A kind of method for designing of urban rainwater pipeline

Technical field

The present invention relates to a kind of method for designing of urban rainwater pipeline, particularly relate to a kind of method that adopts important design parameter----urban rainstorm intensity formula in the caliber design that the Method of Searching in Curved program calculates urban rainwater pipeline, it is improvement to the Traditional calculating methods of urban rainstorm intensity formula, belong to municipal drainage and Computer Applied Technology field, can be widely used in the caliber design of the calculating of urban rainstorm intensity formula of each department and urban rainwater pipeline.

Background technology

The trend of municipal drainage system is a separate system at present.Be that sewage and rainwater are collected and conveying by sewer line and storm sewer respectively, sewage enters the municipal sewage plant, and rainwater directly enters water body.Therefore, the storm sewer design phiolosophy is: in time, promptly get rid of the surface runoff that rainfall forms.90% of rainfall amount in the city will form runoff according to surveying and determination.Therefore, along with urban development, the rainfall runoff amount will increase greatly, if the design of the caliber of urban rainwater pipeline is improper, then rainfall runoff can not be discharged fast, thereby cause damage for urban construction and people's lives.

Basic basis as urban flood defence and Drainage Design is the storm intensity prediction, and whether it accurately is directly connected to science and economic rationality with urban infrastructure construction.And the core of predicting as storm intensity is a urban rainstorm intensity formula, traditional urban rainstorm intensity formula of setting up, generally count the rainfall data certainly according to local observatory (station), the employing statistical calculation method determines, exist waste time and energy, poor accuracy, statistical data is many and the big shortcoming of amount of calculation.

Provide advanced method reliably for setting up urban rainstorm intensity formula fast and accurately, a lot of people had proposed to use the curved surface least square method to solve the general process of parameter optimization in the urban storm formula is inquired in recent years, but because the curved surface in the binary space that the base curve that the curved surface least square method is derived is reoccurrence period P and rainfall duration t to be represented, so this method can only be calculated the total formula of Rain Intensity Formula Based.

Summary of the invention

The objective of the invention is to overcome the prior art above shortcomings, by existing method of inquiring into the urban storm formula with the curved surface least square method is improved, provided a kind of method that adopts Method of Searching in Curved to inquire into the urban rainwater pipeline design of urban storm formula.The represented curved surface of Method of Searching in Curved of the present invention is the curved surface that is made of rainfall duration corrected parameter b and rainfall attenuation index n, so it not only can calculate total formula, can also calculate the branch formula of storm intensity.And the method is compiled into computer program with the VB language, inquire into Rain Intensity Formula Based, and calculate urban rainwater pipeline with this.Method of Searching in Curved of the present invention is under the accuracy prerequisite that guarantees the result, that has improved formula greatly inquires into speed and computational accuracy, by contrast and practical proof, the present invention has advantages such as fast convergence rate, better numerical value stability, to present stage each city large tracts of land of China to inquire into Rain Intensity Formula Based be an important supplement.

The technical scheme that the present invention provides is: the method for designing of this urban rainwater pipeline includes the following step:

1. use the computing machine to support Visual Basic 6.0, the city rainfall source book the grasped form with database or text is input in the computing machine;

2. call original rainfall data in the hard disk in calculator memory RAM, in central processor CPU, carry out data preparation;

3. to carrying out frequency analysis, draw the i-t-P table, convey to the display of terminal through the data after the rough handling;

4. call " Method of Searching in Curved program " by central processing unit (CPU), and existing i-t-P table is calculated, and then inquire into and urban rainstorm intensity formula;

5. use Rain Intensity Formula Based calculate the caliber of urban rainwater pipeline, and with the printer output of terminal.

Purpose to better implement the present invention when adopting the Method of Searching in Curved program to inquire into urban rainstorm intensity formula, includes the following step

(1). Automatic Program imports required derivation of equation condition i-t-P table;

(2). the region of search of determining parameter b is [0,20], and gives b with its difference assignment ₁And b ₂

(3). use Fibonacci method that the b value is searched in the interval; Earlier a less value is composed and given b ₃, at b ₃Condition under the same value of using the golden search method to ask parameter n, the region of search of n value is [0,2]; Obtain just can continuing to use the formula of least square method to try to achieve two other parameter A after the optimal value of parameter b, n ₁With the value of C, and calculate error value E F1 under this parameter; In like manner, bigger value is composed to b ₄After, at b ₄Condition under obtain the value of parameter n, and then obtain parameter A ₁With the value of C, and calculate error value E F2 under this parameter;

(4). two error of calculation EF1 and EF2 are compared; If EF1＜EF2 is then b ₁Assignment is given b ₁, b ₄Assignment is given b ₂If EF1＞EF2 is then b ₃Assignment is given b ₁, b ₂Assignment is given b ₂If EF1=EF2 is b ₁Assignment is given b ₁, b ₄Assignment is given b ₂

(5). judge b ₁And b ₂Difference | b ₁-b ₂| whether enough little, promptly | b ₁-b ₂|＜ε;

(6). the result is for being, then can obtain parameter b value and with its relevant parameters n, A ₁Value with C;

(7). finish;

The result of step (5) then by the value of new region of search search parameter b, turns back to the starting end of step (3) for not.

Principle of the present invention is:

With four parameter A in the Rain Intensity Formula Based ₁, C, n, b regard variable as, and be designated as:

$f(A_1,C,b,n)=\frac{A_1(1+\mathrm{ClgP})}{{(t+b)}^n}$

What following formula was represented is a nonlinear curve, and by to four parameter analyses in the formula as can be known, when fixing two independents variable of n, b, this formula just is a linear relation.For the problem that fits of linearity curve, can calculate with least square method fully.

1. adopt the computing formula of four parameter least square methods:

A ₁Value

$A_1=\frac{\mathrm{\ΣA}{\mathrm{\Σlg}}^{2}P-\mathrm{\ΣAlgP\ΣlgP}}{\mathrm{r\Σ}{\lg }^{2}P-{\left(\mathrm{\ΣlgP}\right)}^2}=\mathrm{fa}(b,n)$

The number of r-reoccurrence period P in the formula;

The rain power of A-design rainfall is divided the parameter in the formula, can be calculated as follows;

$\mathrm{lgA}=\frac{\mathrm{\Σlgi}+\mathrm{n\Σlg}(t+b)}{m}$

The C value

$C=\frac{\mathrm{\ΣA}-r{A}_1}{\mathrm{\ΣlgT}}/A_1=\mathrm{fc}(b,n)$

2. can adopt the computing formula of curved surface least square method equally:

The C value

$C=\frac{\mathrm{\ΣlgP\Σ}\frac{i}{{(t+b)}^n}-\mathrm{m\Σ}\frac{\mathrm{ilgP}}{{(t+b)}^n}}{\mathrm{\ΣlgP\Σ}\frac{\mathrm{ilgP}}{{(t+b)}^n}-\mathrm{\Σlg}{P}^2\mathrm{\Σ}\frac{i}{{(t+b)}^n}}=\mathrm{fc}(b,n)$

A ₁Value

$A_1=\frac{\mathrm{\Σ}\frac{i(1+\mathrm{ClgP})}{{(t+b)}^n}}{\mathrm{\Σ}\frac{{(1+\mathrm{ClgP})}^2}{{(t+b)}^{2n}}}=\mathrm{fa}(b,n)$

Facts have proved and use the 2. to plant formula higher by about 0.001 than the computational accuracy of 1. planting.So we are parameter A ₁, C regards the function of n, b as, and Rain Intensity Formula Based become:

$f(A_1,C,b,n)=\frac{\mathrm{fa}(b,n)(1+\mathrm{fc}(b,n)\mathrm{lgP})}{{(t+b)}^n}=g(b,n)$

Because least square method can only solve linearity or can linearizing function fitting problem, in any case and following formula all is can not be linearizing, so be all its optimum solutions not necessarily of four parameter least square methods or the value of separating of curved surface least square method.

Along with the development of computing machine, make us on parameter b, two-dimensional space that n constituted, directly seek optimal value.The simplest way is formatted b, n two-dimensional space infinite net with certain spacing exactly, searches for optimum solution.In order to accelerate search speed, can search for the interval at optimum solution place with Fibonacci method, this interval constantly is compressed to prescribed level, then separating for former problem.

Curve fitting solution formula parameter is exactly to ask the extreme value of following formula.

$H=\underset{k=1}{\overset{m}{\mathrm{\Σ}}}{[g(b,n)-i]}^x$

H is a parameter A in the formula ₁, C, b, n functional (definition of functional: establishing { y (x) } is the collection of functions of having given, if arbitrary function y (x) perseverance hereto in the function set has certain number of determining corresponding with it, be designated as ∏ [y (x)], remember that then ∏ [y (x)] is a functional that is defined in the set { y (x) }), when x=2, this functional becomes following formula:

$Q(b,n)=\underset{k=1}{\overset{m}{\mathrm{\Σ}}}{[g(b,n)-i_k]}^2$

This formula is the objective function formula.

Compared with prior art, the invention has the beneficial effects as follows: under the accuracy prerequisite that guarantees the result, that has improved formula greatly inquires into speed and computational accuracy, simultaneously can also avoid occurring mistake, further reduced the error of formula, by contrast and practical proof, the present invention has advantages such as fast convergence rate, better numerical value stability, to present stage each city large tracts of land of China to inquire into Rain Intensity Formula Based be an important supplement.

Description of drawings

Fig. 1 provides the process chart of embodiment for the present invention;

Fig. 2 inquires into flow chart when urban rainstorm intensity formula for adopting the Method of Searching in Curved program among Fig. 1.

Judge the direction of arrow of selecting part among the figure, laterally represent not that vertical expression is.

Embodiment

As shown in Figure 1, the method for designing of this urban rainwater pipeline, include the following step: 1. use the computing machine that to support Visual Basic 6.0, manually be input in computing machine with the form of database or text the city rainfall source book grasped, and in hard disk, store, the difference of number decides the size of hard disk remaining space according to original rainfall data year, generally is not less than 20M; 2. call original rainfall data in the hard disk in calculator memory RAM, the data processing function of appliance computer itself carries out data preparation in central processor CPU, because the needs of arithmetic speed require the processor of Pentium more than three in principle; 3. to carrying out frequency analysis, draw the i-t-P table, convey to the display of terminal, and the i-t-P table is stored in the hard disk, in order to using through the data after the rough handling; 4. call " Method of Searching in Curved program " by central processing unit (CPU), and existing i-t-P table is calculated, and then inquire into and urban rainstorm intensity formula, and the gained data are backuped in hard disk; 5. use Rain Intensity Formula Based calculate the caliber of urban rainwater pipeline, and with the printer output of terminal.

As shown in Figure 2, when adopting the Method of Searching in Curved program to inquire into urban rainstorm intensity formula, including the following step (1). Automatic Program imports required derivation of equation condition i-t-P table; (2). the region of search of determining parameter b is [0,20], and gives b with its difference assignment ₁And b ₂(3). use Fibonacci method that the b value is searched in the interval; Earlier a less value is composed and given b ₃, at b ₃Condition under the same value of using the golden search method to ask parameter n, the region of search of n value is [0,2]; Obtain just can continuing to use the formula of least square method to try to achieve two other parameter A after the optimal value of parameter b, n ₁With the value of C, and calculate error value E F1 under this parameter; In like manner, bigger value is composed to b ₄After, at b ₄Condition under obtain the value of parameter n, and then obtain parameter A ₁With the value of C, and calculate error value E F2 under this parameter; (4). two error of calculation EF1 and EF2 are compared; If EF1＜EF2 is then b ₁Assignment is given b ₁, b ₄Assignment is given b ₂If EF1＞EF2 is then b ₃Assignment is given b ₁, b ₂Assignment is given b ₂If EF1=EF2 is b ₁Assignment is given b ₁, b ₄Assignment is given b ₂(5). judge b ₁And b ₂Difference | b ₁-b ₂| whether enough little, promptly | b ₁-b ₂|＜ε; (6). the result is for being, then can obtain parameter b value and with its relevant parameters n, A ₁Value with C; (7). finish; The result of step (5) then by the value of new region of search search parameter b, turns back to the starting end of step (3) for not.

The present invention inquires into the detailed process of urban rainstorm intensity formula parameter, and also available the following step is described:

The first step: in interval [0,20], release rainfall duration corrected parameter b with Fibonacci method.

Second step: in interval [0,2], release rainfall attenuation index n with Fibonacci method.

The 3rd step: use formula to release rain variation parameters C.

$C=\frac{\mathrm{\ΣlgP\Σ}\frac{i}{{(t+b)}^n}-\mathrm{m\Σ}\frac{\mathrm{ilgP}}{{(t+b)}^n}}{\mathrm{\ΣlgP\Σ}\frac{\mathrm{ilgP}}{{(t+b)}^n}-\mathrm{\Σlg}{P}^2\mathrm{\Σ}\frac{i}{{(t+b)}^n}}=\mathrm{fc}(b,n)$

The 4th step: using formula to release the reoccurrence period is the rain force parameter A of the design rainfall in 1 year ₁

$A_1=\frac{\mathrm{\Σ}\frac{i(1+\mathrm{ClgP})}{{(t+b)}^n}}{\mathrm{\Σ}\frac{{(1+\mathrm{ClgP})}^2}{{(t+b)}^{2n}}}=\mathrm{fa}(b,n)$

The 5th step: use the total formula parameter A of releasing ₁, C, b, n, calculate rainfall intensity.

$g(b,n)=\frac{\mathrm{fa}(b,n)(1+\mathrm{fc}(b,n)\mathrm{lgP})}{{(t+b)}^n}$

The 6th step: the value that can obtain the rain force parameter A of design rainfall according to formula.

$\mathrm{lgA}=\frac{\mathrm{\Σlg}\left[g(b,n)\right]+\mathrm{n\Σlg}(t+b)}{m}$

The total item of m in the formula---rainfall duration.

So far, the parameter of Rain Intensity Formula Based total formula and branch formula all inquires into out.

Claims (2)

1. the method for designing of a urban rainwater pipeline is characterized in that including the following step:

1.. use can be supported the computing machine of Visual Basic 6.0, manually is input in computing machine with the form of database or text the city rainfall source book grasped;

2.. call original rainfall data in the hard disk in calculator memory RAM, in central processor CPU, carry out data preparation;

3.. to carrying out frequency analysis, draw the i-t-P table, convey to the display of terminal through the data after the rough handling;

4.. call " Method of Searching in Curved program " by central processing unit (CPU), and existing i-t-P table is calculated, and then inquire into and urban rainstorm intensity formula;

5.. use Rain Intensity Formula Based calculate the caliber of urban rainwater pipeline, and with the printer output of terminal.

2. the method for designing of urban rainwater pipeline according to claim 1 is characterized in that including the following step when adopting the Method of Searching in Curved program to inquire into urban rainstorm intensity formula

(1). Automatic Program imports required derivation of equation condition i-t-P table;

(2). the region of search of determining parameter b is [0,20], and gives b with its difference assignment ₁And b ₂

(3). use Fibonacci method that the b value is searched in the interval; Earlier a less value is composed and given b ₃, at b ₃Condition under the same value of using the golden search method to ask parameter n, the region of search of n value is [0,2]; Obtain just can continuing to use the formula of least square method to try to achieve two other parameter A after the optimal value of parameter b, n ₁With the value of C, and calculate error value E F1 under this parameter; In like manner, bigger value is composed to b ₄After, at b ₄Condition under obtain the value of parameter n, and then obtain parameter A ₁With the value of C, and calculate error value E F2 under this parameter;

(4). two error of calculation EF1 and EF2 are compared; If EF1＜EF2 is then b ₁Assignment is given b ₁, b ₄Assignment is given b ₂If EF1＞EF2 is then b ₃Assignment is given b ₁, b ₂Assignment is given b ₂If EF1=EF2 is b ₁Assignment is given b ₁, b ₄Assignment is given b ₂

(5). judge b ₁And b ₂Difference | b ₁-b ₂| whether enough little, promptly | b ₁-b ₂|＜ε;

(6). the result is for being, then can obtain parameter b value and with its relevant parameters n, A ₁Value with C;

(7). finish;

The result of step (5) then by the value of new region of search search parameter b, turns back to the starting end of step (3) for not.

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